ICP-AES and MicroRaman corrosion behaviour investigation on Zn4Sb3 and Al, Ag doped phases in sodium chloride solution

The high thermoelectric performance of the β-phase Zn4Sb3 has drawn much attention for its application in the intermediate temperature range. In this work we explore the corrosion behaviour properties of pure Zn4Sb3 compound and after partial substitution of Zn with Al and Ag. In particular, Zn4Sb3, (Zn1xAlx)4Sb3 and (Zn1xAgx)4Sb3 (x = 0.01) compounds were synthesized using a muffle furnace and characterized in terms of crystal structure, morphology and phases composition (SEM-EDXS, XRD). All samples were placed in 0.1 M NaCl aerated solution at room temperature for 48 days. A study of the amount of cations released in solution was carried out using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) analysis. Analytical data reveal a higher value of zinc amount for doped samples. The microRaman spectroscopy analysis carried out on surface corrosion products revealed the presence of anhydrous and hydrate zinc hydroxy chlorides. No worsening on corrosion behaviour of Zn4Sb3 intermetallic compounds was observed after Al or Ag doping.